An excerpt --
"Where are cities most dense? Look no further than Asia, where concentrated economic growth has spawned 16 of the 20 densest urban areas in the world, according to 2007 statistics from citymayors.com. Leading the way are Mumbia and Kolkata, both in India, each of which pack in over 23,000 people per square kilometer. Both cities, along with those close behind like Karachi, Pakistan, Lagos, Nigeria and Shenzhen, China, hold about as many people within a handful of square blocks as live in U.S. metros like Charleston, S.C., Green Bay, Wis., or Berkeley, Calif."
Read the full story at --
http://www.forbes.com/2007/12/14/cities-pollution-asia-biz-logistics-cx_tvr_1214densecities.html